Lewisbázisként

Lewisbázisként is a chemical term referring to a substance that can donate a pair of electrons to form a coordinate covalent bond. This definition is part of the Lewis acid-base theory, which describes acid-base reactions in terms of electron pair transfer. A Lewis base, by definition, is an electron pair donor. This electron pair is typically found in a lone pair on an atom within the molecule or ion.

Common examples of Lewis bases include ammonia (NH3), where the nitrogen atom has a lone pair of electrons, and water (H2O), where oxygen possesses lone pairs. Many anions, such as hydroxide (OH-) and chloride (Cl-), also act as Lewis bases due to their negative charge, which implies an abundance of electrons. The interaction between a Lewis base and a Lewis acid results in the formation of an adduct, a new chemical species where the electron pair from the base is shared with the electron pair acceptor.

The concept of Lewis bases is broader than the Brønsted-Lowry definition of bases, which are proton acceptors. While many Brønsted-Lowry bases are also Lewis bases, the Lewis definition encompasses reactions that do not involve protons. For instance, the reaction between boron trifluoride (BF3), a Lewis acid, and ammonia (NH3), a Lewis base, forms a stable adduct, illustrating the electron pair donation from ammonia to boron. Understanding Lewis bases is crucial in various areas of chemistry, including organic synthesis and coordination chemistry.